The inner bushing does not have the oil groove but should have the beveled edge toward the inside. This bevel is needed to correctly mate up with the bevel shoulder on the crankshaft. The picture on the right demonstrates the section of a twin cylinder crankshaft that is used to properly seat the bushing. The short crankshaft section will match the bevel of the bushing and will stop moving when the bushing is flush with the inside edge of the housing.

The left image shows the inside bushing as it is beginning to be pressed into the housing. The image pictured on the right demonstrates the position of the tools as the inner bushing is correctly seated.

The inner bushing should be drilled with a 3/16" bit through the hole in the S-234 housing to provide an oil passageway at the top of the bushing.